Direct numerical simulation of passive scalar in decaying compressible turbulence
نویسندگان
چکیده
The passive scalars in the decaying compressible turbulence with the initial Reynolds number (defined by Taylor scale and RMS velocity) Re=72, the initial turbulent Mach numbers (defined by RMS velocity and mean sound speed) Mt=0.2-0.9, and the Schmidt numbers of passive scalar Sc=2-10 are numerically simulated by using a 7 order upwind difference scheme and 8 order group velocity control scheme. The computed results are validated with different numerical methods and different mesh sizes. The Batchelor scaling with 1 − k range is found in scalar spectra. The passive scalar spectra decay faster with increasing the turbulent Mach number. The sheet-like structures of the passive scalar gradient are also founded. The extended self-similarity (ESS) is found in the passive scalar of compressible turbulence. Keyword: passive scalar, decaying compressible turbulence, direct numerical simulation
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